Byssinosis, a common and crippling disease among several categories of textile workers, is characterized by symptoms of airway constriction of first working days after absence from work, and by the development of severe and irreversible ventilatory insufficiency after many years of exposure to various textile dusts. A better understanding of physiological and pharmacological mechanisms of the action of textile dusts on the lungs is urgently needed now that byssinosis is increasingly being recognized as a significant health problem in the cotton textile industry in the United States. This proposal includes chemical, biochemical, pharmacological, epidemiological and medical studies designed to increase our understanding of the nature of the disease and of the methods that can be used to control and prevent it. These include: (1) determination of the chemical nature of the pharmacological agent(s) in textile dust which cause airway constriction in man; (2) investigations of the mechanisms by which textile dusts affect the airways and the lungs; (3) study of the factors that determine the inter-individual variability of airway responses to textile dust; (4) assessment of the importance of disabling respiratory disease among textile workers as a public health problem. Data on the prevalence of disabling lung disease among retired textile workers are crucial to determine how often early byssinosis progresses to disabling disease, and to determine the time course of the progression of the disease.